1. Field of the Invention
The present invention relates to an image forming apparatus, a return processing method, and a program.
2. Description of the Related Art
In recent years, as measures for environmental protection, energy conservation measures have been taken in the various fields. Even the field of an image forming apparatus, such as a copier and a printer, is no exception, and various kinds of efforts for energy conservation have been made in the design of the image forming apparatus.
For example, as a typical way to reduce power consumption, after a certain period of time has elapsed since a copier has not been in operation, the operation mode is switched to an energy-saving mode in which part of the copier that consumes relatively high power, such as an engine unit, is powered off, and after a certain additional period of time has elapsed, a controller unit goes into a sleep mode, and the operation state of the copier is switched to the one in a low-power mode.
As an energy conservation measure that comes from a different mindset, there has been proposed a power consumption limiting system that divides users into groups, accumulates electric energy consumed for execution of jobs in each group on a group-by-group basis, and limits execution of a job in a group of which the accumulated total electric energy exceeds an upper limit of electric energy assigned to the group (see Japanese Patent No. 3428590).
Furthermore, as another energy conservation measure, there has been proposed a “power monitoring network system” that estimates the month's electric energy consumption of an image forming apparatus on the basis of history information, and determines whether the estimated electric energy consumption exceeds available maximum electric energy set in advance (see Japanese Patent Application Laid-open No. 2007-159298).
In this power monitoring network system, if the estimated electric energy consumption exceeds the maximum electric energy, a power management device preliminarily performs a simulation process for calculating electric energy consumption that can be reduced by changing the setting of use conditions of the apparatus on the basis a power reduction level set according to the excess electric energy consumption. By performing the simulation process, appropriate use conditions capable of preventing electric energy consumption from exceeding the maximum electric energy are determined.
Moreover, as still another energy conservation measure, there has been proposed a method for optimizing the time to make the transition to an energy-saving mode by storing the state transition to a standby mode or the energy-saving mode and learning the use frequency and content (see Japanese Patent Application Laid-open No. 2008-072391).
In the power consumption limiting system disclosed in Japanese Patent No. 3428590, it can be expected that users belonging to each group are more conscious of saving on electricity and make efforts for it, which leads to the promotion of energy conservation; however, a limitation on the use is placed only if electric energy consumption exceeds the upper limit, which means no limitation is placed until electric energy consumption exceeds the upper limit.
Furthermore, the power monitoring network system disclosed in Japanese Patent Application Laid-open No. 2007-159298 is aimed at improving the accuracy of calculation of future electric energy consumption, and any means to limit electric energy consumption is not particularly described in Japanese Patent Application Laid-open No. 2007-159298.
Moreover, with a method for setting a transition period disclosed in Japanese Patent Application Laid-open No. 2008-072391, the transition time can be optimized and energy conservation can be improved without bothering a user with a troublesome operation (settings of the times to make the transition to multiple energy-saving modes, etc.). However, this method is aimed at determining a transition pattern, and as a means to limit electric energy consumption, the start time (the return time) is not subject to the energy conservation measure.
In considering an energy conservation measure in an MFP (Multi Function Peripheral) or an LP (Laser Printer) (hereinafter, referred to as simply “the apparatus”), conventionally, energy conservation is achieved by switching the mode, for example, to an energy-saving mode; however, even in a case of restraining total electric energy consumption, as described in Japanese Patent No. 3428590, electric energy consumption is restrained after it exceeds an upper limit, and no energy conservation measure is taken unless the electric energy consumption exceeds the upper limit.
In the apparatus, together with the energy conservation measure described above, various measures to improve the operating rate, i.e., improve the productivity are implemented.
For example, reduction of the time to return from a standby state in which the apparatus is in an energy-saving mode to a ready state in which the apparatus is ready for operation is performed. This is because the shorter the return time is, the higher the productivity, resulting in an increase in the operating rate. Namely, for example, if a job that takes 3 minutes is repeated with the standby time of 1 minute and the return time of 10 seconds, 14.4 jobs can be executed in an hour. If the return time is 1 minute, 12 jobs can be executed in an hour, which means a difference of about 2 jobs and a difference of about 6 minutes in the operating time are made.
Furthermore, to reduce the return time of the apparatus, even when the apparatus is not in operation, for example, the apparatus is in a standby mode or the energy-saving mode, residual heat is always applied to a fixing unit of an engine unit.
Moreover, as the size of software of a controller is enlarged today, it takes time to load an object and initialize it, and the return time of the apparatus tends to be prolonged; therefore, the controller is powered on with the software be resident in a memory, thereby reducing the return time.
In this manner, currently, some power consumption is sacrificed to improve the operating rate of the apparatus while trying to conserve energy of the apparatus.
Consequently, there has been expected energy conservation measures capable of achieving energy conservation while maintaining the operating rate of the apparatus appropriately, i.e., energy conservation measures balanced for both the operating rate of the apparatus and energy conservation.